Air control for oil-burning furnaces



G. C. G. GRAY. AIR CONTROL FOR OIL BURNING FURNACES. APPLICATION FILED ocT.20, 1919.

1,373,501'. Patented Apr. 5, 1921.

' AEl By i UNITED STATES PATENT OFFICE.

AIR CONTROL FOR OIL-BURNING FURNACES.

Speccationgof Letters Patent.

Patented Apr. 5, 1921.

Application filed October 20, 1919. Serial No. 332,040.

To all 'whom 'it may concer/n.'

Be it known that I, Grenen C. G. GRAY, a citizen of the United States, residing at the city of Philadelphia, in the county of Philadelphia and State of Fennsylvania, have invented a certain new and useful lmproved Air Control for Oil-Burning Furnaces, of which the following is a specification.

rlhis invention has relation to steam boilers, the furnaces of which are fired with oil fuel and has more particular relation to air control therefor.

As commonly practised in the art, air is admitted at a furnace front and is permit ted to pass upwardly through permanently open apertures in the furnace floor for sup` porting combustion. Since no means are present for closing or partially closing these apertures, it frequently happens that too much oxygen is present in the fuel gases with the result that imperfect combustion takes place, and a loss of heat units occurs.

lt is the leading object of the present invention to overcome this disadvantageous feature, and provide air controlling means whereby the highest possible percentage of C02 and the least possible percentage of O and CU may be maintained in the combustion chamber of an oil-burning furnace in order to eliminate loss of heat units and gain substantially perfect combustion. A further object of the present invention is to provide a system of damper control where by air may be admitted to a combustion chamber in selective quantitiesv at desired points or may be entirely shut 0H from said chamber as desired. A further object of the present invention is to control these dampers from a central point by operating means common to all the dampers. A still further object resides in the provision of means whereby air is admitted through the rear of a furnace and is permitted to pass beneath the floor for pre-heating purposes prior to admission to the combustion chamber. lNith these `and other objects in view the invention consists of the improvements hereinafter described and iinally claimed.

The nature, characteristic features and scope of the invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof and in which:

Figure 1, is a view 1n longitudinal section of an oil-burning furnace equipped with air controlling means embodying features of the invention.

Fig. 2, is a view in horizontal section talren upon the line 2-2 of Fig. 1, and

Fig. 3, is a fragmentary view, in section, drawn to an enlarged scale and illustrating the foremost damper in open position.

For the purpose of illustrating my invention I have shown in the accompanying drawings one form thereof which is at present preferred by me since the same has been found in practice to give satisfactory and reliable results, although, it is to be understood that the various instrumentalities of which my invention consists can be variously arranged and organized and that my invention is not limited to the precise arrangement and organization of the instrumentalities as herein shown and described.

In the drawings, 10, designates a boilersetting of Vany desired type. Projected through the fire-door, 11, thereof, is an oilburner, 12, which may he of any well known form. According to the present invention l remove the usualv grate and bridge-wall and construct a furnace-floor which inclines slightly from the front to the rear walls of the boiler-setting. Such floor may be constructed of tiles, 13, having interlocked relation, as at 14C, to form air tight joints and is supported upon suitable crosspieces 15. A. desired number of the forward tiles are each provided with an air-duct, 16, forming communication between the pit, 17, and combustion chamber, 18. As clearly shown in Fig. 3, these ducts are so formed as to direct air currents in the same direction as the flame from the burner. The lower part of each tile having an airmduct therethrough is disposed in' a plane which lintersects the horizontal plane of a tile proper and the under face thereof is flat. Extended across the boiler-setting beneath each tile having an air-duct there may be a pivotal-rod, 19. Fixed to leach rod is a'damper, 20, for abutting against the under face of a tile for closing an air-duct. Also fixed to each rod is a lever, 21, provided with a counter-weight, 22. These levers are preferably arranged at one side of the combustion chamber. Various means may be designed for operating these dampers. In the drawings, I have shown for illustrative purposes, a simple form of operating means. Pivoted as at 23, to the front of the boiler-setting is a lever,

24, extended laterally from which there may be a pin, 25. Connecting the lever of each damper with said pin, 25, is a flexible connection, as a chain, 26. As shown in Fig. I, these chains are permitted a certain amount of slack so that, when lever, 24, is moved outward for instance, the frontmost damper may be opened before the slack of the chain of the next damper is taken up, and so on. Thus air may be permitted to pass to the combustion chamber through a duct, while the balance ofthe ducts remain closed or partially closed. A guide-piece, 27, may

be provided for the lever, 24, and means as a nut, 28, may be present for locking said lever to the said guide in desired damper positions. I prefer to admit air to the pit beneath the furnace floor through an opening, 28', in the rear of the boiler-setting.

Thus, air as it travels forward beneath the tiles, is preheated before it passes to the combustion chamber.

In the operation of the above described apparatus let it be assumed, for illustrative purposes, that a test of gases in the combustion chamber is to be made and let it further be assumed that all. the dampers are open. It is found that too much oxygen is present in the gases. Accordingly, the operator in charge moves lever, 24, inwardly and permits the foremost damper to close or partially close which it does by reason of the counter-weight connection. If too much oxygen is still present the next damper is permitted to close or partially close and so on until theV highest possible percentage of carbon dioxid (CO2) and the least possible percentage of oxygen (O) and carbon monoxid (CO) is obtained. Thus, the loss of heat units is eliminated and a relatively perfect mixture of air and fuel for combustion is obtained.

It will now be apparent that I have devised a novel and useful construction which embodies the features of advantage enumerated as desirable in the statement of the invention and the above description and while I have in the present instance shown and described the preferredembodiment thereof, which has been found in practice to give satisfactory and reliable results, it is to be understood that the same is susceptible of modification in various particulars without departing from the spirit or scope'of the invention or sacrificing any of its advan tages. Y

TWhat I claim is:

1. Apparatus of the characterstated com prising a furnace having a combustion chamber and an air chamber, a floor of refractory material separating said chambers, a plurality of air ducts forming means of communication between said chambers, a movable closure for each duct, operatingmeans common to all of said closures for controlling the passage of air through a selected number of air chiots and a burner for heating said furnace.

2. Apparatus of the character stated comprising a furnace having a combustion chamber and an air chamber, a floor of refractory material separating said chambers, a plurality of air ducts establishing communication between said chambers, a pivoted damper for each duct, operating means common to all of said closures for controlling the passage of air through a selected number of air ducts and a burner forfheating said furnace.

3. A construction as descrlbed 1n claim 2,

vcharacterized by dampers which are selfclosing upon release.

4. Apparat-us of the character stated comprising a furnace having a combustion chamber and an air chamber, a floor of refractory material separating said chambers, a plurality of air ducts forming means of communication between said chambers each air duct being shaped and proportioned for directing air in the Vdirection ofthe passage of flame from a burner, a burner'forheatf ing said furnace, a movable closure for each duct ano operating means common to all of said closures forl controlling the passage of air through a selected number of ducts. Y

5. construction as described in claim 4, characterized by means open for the constant introduction of air to the air chamber in a direction opposite to that of the passage of flame from the burner. f

6. Apparatus of the character stated comprising a furnace having a combustion chamber and an air chamber, a floor of refractory material separating said chambers, a plurality of air ducts for establishing comnuinication between said chambers, a self closing damper for each duct, an operating medium, a flexible connection between each damper and said operating medium and a burner for heating said furnace.

7. A construction as described in claim 6, characterized by means for loclring the operating medium against retrograde movement in the open position of a damper.

In witness whereof I have hereunto signed my name.

Gnonsnc. G. GRAY. 

